Packing for pistons.



G. HONEGGER.

PACKING FOB PISTONS.

APPLICATION FILED MAY 25, I917- Patented Nov. 12, 1918..

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Specification of Letters Patent.

Application filed May 25, 1917. Serial No. 170,924.

To all whom it may concern Be it known that I, GUSTAV Honnccnn, a citizen of the Republic of Switzerland, residing at Zollikon, near Zurich, Riitistrasse 325, Switzerland, have invented certain new and useful Improvements in Packings for Pistons; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and usethe same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

The present invention relates to packings for pistonsand has for its object to provide automatic devices for readjusting such packing in such a manner that its tightness depends on and is controlled by the working pressure is admitted to the bore the working pressure.

Packings" of this kindhav'e not so far been proposed. Disk pistons have been provided either with spring rings when the may be employed for low pressure wor only, or else with leather collars only suitable for work with cold, chemically pure liquids. Again, with plunger pistons, inner or outer packings may be used but these have to be readjusted by hand from within or from without.

According to this invention, automatic readjustment of'a piston-packing is caused by the working pressure being admitted into the interior of a diaphragm ring which is arranged in the disk piston andwhich by expanding under the action of such pressure forces the packin material outward and against'the wall 0 the pump cylinder. It will be seen that in this case the tightness 'of the packing or the force acting on the packing material is dependent on and automatica y controlled by the working pressure.

The accompanying drawings represent different designsconstructed according to this invention.

Figure 1 shows a disk piston having a single diaphragm ring and a valve governed by the working pressure and serving to connect the inner space of the diaphragm ring with the pressure side of the pump.

Fig. 2 shows a disk piston having two diaphragm rings either ofwhich constantly communicates with the adjacent piston side. Referring now to Fig. 1, the construction there shown is as follows.

1 is a piston rod upon which are secured the disk piston 2 and the junk ring 3. In-

closing the piston body 2 is a diaphragm rlng 1 within which an expanding rin 5 Wlth opening 6 is arranged. The iaphragm rin 4: is pressed against the piston body 2 by t e junk ring 3 and is held tight by means of-packings 7 Drilled through the plston body 2 is a bore 8 in which a valve is movable between two valve seats 10 having'openings 11. Inclosing the diaphragm ring 4: is a split spring ring 12 carrymg the packing material 13. A hole 1 1 in the piston body 2 connects the opening 6 to the bore 8, while bores 15 are held closed by means of spring valves 16. In the design shown in Fig. 1 the action of the parts is the following:

At the beginning of each piston stroke,

f8 and forces-the valve 9 backward against its left-hand seat 10, so that the hole 14 is Patented Nov.12, 1918.

cleared and the interior of the diaphragm ring 1, while out ofi from the suction side, is put under working pressure. This causes the diaphragm and the split spring ring 12 to expand in a radial sense, so that the packing material isforced out against the cylindeiilwall and the piston is automatically held tig t.

Expansion of the diaphragm ring continues until the end of the stroke, when the valve 9 is forced back against its righthand seat and the working pressure is admitted to the diaphragm from the opposite side of the piston. In order to avoid backpressure acting on the outside of the diaphragm ring and thereby counter-acting the expanding force of the compressed llquid in the interior of the diaphragm ring, the

outer surface of the latter is kept in combores 8 are drilled into it and these com-- municate through holes 14 with the openings 6. Inclosing each diaphragm ring 4 is a split spring ring 12 and these rings carry the packing material 13. Bores such as 15, 17 and 18 are provided to connect the outer surface of the diaphragm ring with the suction pipe (not shown) of the pump.

In the design shown in Fig. 2, the action of theparts is as follows.

At the beginning of each piston stroke, the bores 8, 14: and 6 admit working pressure to the interior of that diaphragm ring which is on the pressure-side of the piston. This causes the diaphragm ring and the split ring 12 to expand in a radial sense, so that the packing material is forced out against the cylinder wall and the piston is automatically held tight.

While the interior of the diaphragm ring is kept under working pressure, its outer circumference is automatically relieved by being connected with the suction side through bores 15, 17 and 18,

When one of the diaphragms is under working pressure, the other one, adjacent to the suction side, remains relieved.

When the motion of the piston is reversed,

, obviouslythe diaphragm which has been under pressure till then will be relieved and vice versa.

If desired, the pressure admitted into the interior of the diaphragm can be made independent of the working pressure by being derivedfrom outside through a bore in the piston rod. i

What I claim is:

1. A piston of the character described, comprising a piston body, a resilient diaphragn ring held fast at the open inner circumference by said piston body but'freely movable at the outer circumference and at the lateral surfaces, said surfaces being so formed that the outer circumference can execute a radial resilient movement, packing material arranged around the outer circumference of the resilient diaphragm ring, and means for supplying a pressure medium into the interior of the said diaphragm ring.

2. A piston of the character described, comprising a piston body, a. resilient diaphragm ring held fast at the open inner cir cumference by said piston body but freely movable at the outer circumference and at the lateral surfaces, which latter converge from the outer diameter of the diaphragm ring toward its inner diameter so that its outer circumference can execute a radial resilient movement, packing material arranged around the outer circumference of th resilient diaphragm ring, and means'for supplying a pressure medium into the interior of the said diaphragm ring.

3. A piston of the character described, comprising a piston body, a resilient diaphragm ring held fast at the open inner circumference by said piston body but freely movable at the outer circumference and at thelateral surfaces, said surfaces being so formed that the outer circumference can exe- .cute a radial resilient movement, packing material arranged around the outer circumference of the diaphragm ring, means for supplying a pressure medium into the interior of the said diaphragm ring, packing material arranged around the outer circumference of the resilient diaphragm ring, and means for relieving the'space inclosing the outer circumference of the diaphragm ring of any overpressure occurring in said space, whereby the outward pressure of the diaphragm ring is not counteracted. I

4. A piston of the character described, comprising a piston body, a resilient diaphragm ring disposed in an annular recess of said body and held fast on said body by turned-out edges which form the open inner circumference, said ring being freely movable at the outer circumference and at the lateral surfaces, which latter are formed so that the outer circumference can execute a radial resilient movement, said piston body being provided with holes through which the working pressure is admitted into the interior of the diaphragm ring, and packing material arranged around the outerv circumference of said diaphragm ring.

5. A piston of the character described, comprising a piston body, a resilient ring arranged in an annular recess provided in said piston body, a second resilient diaphragm ring arranged in a second annular recess provided in said piston body, each of said diaphragm rings being held fast at the open inner circumference by said piston body but being freely movable at the outer circumference and at the lateral surfaces, which latter are so formed that the outer circumference can execute a radial resilient movement, packing material arranged around the outer circumference of each resilient diaphragm ring, means for supplying a pressure medium into the interior of the said diaphragm rings, and means for relieving the spaces inclosingthe outer circumference of the diaphragm rings of any overpressure occurring in said spaces, whereby the outward pressure of the diaphragm rings is not counteracted.

6. A piston of the character described, comprising a rod, a disk piston carried by said rod, a junk-ring on either side of the disk piston and carried by said rod, the disk piston and the junk-rings forming two annular spaces, a resilient ring arranged in each of said spaces, said rings being held fast by the piston disk and by the junk-rings on turned-out edges which form the open inner circumference, said ring being freely movable at the outer circumference and at the lateral surfaces which are so formed that the outer circumference can execute a radial resilient movement, packing material arranged around the outer circumference of said spaces being relieved by means of said the resilient diaphragm rings, and means for holes, of any overpressure occurring therein supplying a pressure medium into the inwhereby the outward pressure of the dia- 10 terior of the said diaphragm rings, said disk, phragm rings is not counteracted.

piston and rod being provided with holes In testimony that I claim the foregoing communicating with the spaces inclosing the as my invention, I have si ed m name.

outer circumference of the diaphragm rings, GUSTA H N GGER. 

